Implement a frame tuple accessor class for results which contains just a single serialized string of records without any fields.

git-svn-id: https://hyracks.googlecode.com/svn/branches/fullstack_hyracks_result_distribution@3056 123451ca-8445-de46-9d55-352943316053
diff --git a/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/ResultFrameTupleAccessor.java b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/ResultFrameTupleAccessor.java
new file mode 100644
index 0000000..915a436
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+++ b/hyracks/hyracks-dataflow-common/src/main/java/edu/uci/ics/hyracks/dataflow/common/comm/io/ResultFrameTupleAccessor.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2009-2010 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package edu.uci.ics.hyracks.dataflow.common.comm.io;
+
+import java.io.DataInputStream;
+import java.nio.ByteBuffer;
+
+import edu.uci.ics.hyracks.api.comm.FrameHelper;
+import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor;
+import edu.uci.ics.hyracks.dataflow.common.comm.util.ByteBufferInputStream;
+
+public class ResultFrameTupleAccessor implements IFrameTupleAccessor {
+
+    private final int frameSize;
+    private ByteBuffer buffer;
+
+    public ResultFrameTupleAccessor(int frameSize) {
+        this.frameSize = frameSize;
+    }
+
+    @Override
+    public void reset(ByteBuffer buffer) {
+        this.buffer = buffer;
+    }
+
+    @Override
+    public ByteBuffer getBuffer() {
+        return buffer;
+    }
+
+    @Override
+    public int getTupleCount() {
+        return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize));
+    }
+
+    @Override
+    public int getTupleStartOffset(int tupleIndex) {
+        return tupleIndex == 0 ? 0 : buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * tupleIndex);
+    }
+
+    @Override
+    public int getTupleEndOffset(int tupleIndex) {
+        return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * (tupleIndex + 1));
+    }
+
+    @Override
+    public int getFieldStartOffset(int tupleIndex, int fIdx) {
+        return fIdx == 0 ? 0 : buffer.getInt(getTupleStartOffset(tupleIndex) + (fIdx - 1) * 4);
+    }
+
+    @Override
+    public int getFieldEndOffset(int tupleIndex, int fIdx) {
+        return buffer.getInt(getTupleStartOffset(tupleIndex) + fIdx * 4);
+    }
+
+    @Override
+    public int getFieldLength(int tupleIndex, int fIdx) {
+        return getFieldEndOffset(tupleIndex, fIdx) - getFieldStartOffset(tupleIndex, fIdx);
+    }
+
+    @Override
+    public int getFieldSlotsLength() {
+        return getFieldCount() * 4;
+    }
+
+    public void prettyPrint() {
+        ByteBufferInputStream bbis = new ByteBufferInputStream();
+        DataInputStream dis = new DataInputStream(bbis);
+        int tc = getTupleCount();
+        System.err.println("TC: " + tc);
+        for (int i = 0; i < tc; ++i) {
+            System.err.print(i + ":(" + getTupleStartOffset(i) + ", " + getTupleEndOffset(i) + ")[");
+
+            bbis.setByteBuffer(buffer, getTupleStartOffset(i));
+            System.err.print(dis);
+
+            System.err.println("]");
+        }
+    }
+
+    @Override
+    public int getFieldCount() {
+        return 1;
+    }
+}